Lock Washer, Lock Washer Type Wedge Lock, Finish Delta Protect, Material Steel, For Screw Size 1/4 in, Inside Diameter 0.262 in, Outside Diameter 0.495 in, Maximum Thickness 0.127 in, Assembly Thickness 0.127 in, Color Silver, Material Grade/Class Case Hardened, Pack Size Small Pack, Resistance Properties Shock , Vibration , Rockwell Hardness HRC40, System of Measurement Inch, Package Quantity 200